For powering a paintball marker, you can choose between CO2 or high pressure air, with most players choosing CO2 as these are the cheapest tanks to purchase. While most paintball guns can use either CO2 or compressed air, the more expensive tournament style markers must use high pressure air as CO2 can damage these guns. While ultimately cheaper, CO2 can be hard on any paintball gun however due to its nature. Compared to compressed air, CO2 is more volatile as it converts from gas to liquid (and vice versa) as its used in little spurts each time you pull the trigger of your gun. CO2 is also greatly affected by temperature changes. A properly filled C02 tank will have an internal pressure of about 850 pounds per square inch (psi) in 70 degree (F) temperatures. A temperature increase of one degree will cause the pressure in your tank to rise by 11 psi.
This means the temperature of your playing environment or storage area can affect how your marker will perform with CO2. If you’re playing in an environment of about 70 degrees, when the hot afternoon temperature comes your tank pressure can rise 400+ psi fairly quickly. Without a regulator, this will often cause your gun to shoot hot, possibly even dangerously high. In most cases, CO2 tanks will not overheat as long as they’re in use. Leaving them in the hot sun or in your car while you take lunch during a summer day is often how this happens. If a CO2 tank does overheat, it has a special mechanism (called a ‘burst disc’) that will keep it from causing a dangerous explosion.
The burst disc is a safety pressure relief valve that will rupture if a CO2 tank builds up too much pressure from getting too hot. The result is a spray of CO2 vapor that may cause the tank to spin around a bit until enough pressure is released. If this happens, the best thing to do is get away from it and wait for it to empty or at least stop making hissing noises; after which, the tank is safe to handle again. At this point, you can take the tank to any airsmith at a paintball shop or commercial air tank supply company. The burst disk can be replaced and he can set it to the proper torque, however this is something a professional airsmith should handle to make sure it’s done correctly. If you can’t find a professional airsmith, it may be easier to simply purchase a brand new CO2 tank as they are cheap and easy to find.
Compressed air is the other most common power source used for paintball guns. Compressed air tanks are more expensive than CO2, however their performance is much more consistent. They have built in regulators which reduce the pressure of air fed to the paintball gun to keep it below 800 psi. Most high pressure air tanks for paintball markers range from 3,000 to 5,000psi. When using high pressure air tanks, it’s important to read and follow all of the manufacturer’s instructions regarding usage and storage. Unlike CO2, compressed air is not as sensitive to temperature gradients; this is the main reason why they perform more consistently on the paintball field and are not as volatile to heat. If the burst disk ruptures or a component leaks on a compressed air system, follow the same protocol as with the damaged CO2 tank. The best thing to do is get away from it and wait for it to drain before taking it to a professional for inspection/repair. The leaking high pressure air from a broken gauge can cause serious injury by injecting air under the skin if a body part is held next to it.
All compact CO2 and high pressure air tanks used for paintball guns have a limited life span. CO2 and air tanks have an expiration date stamped on them, usually with 3 to 5 years from the time of purchase. After that the tanks must be tested and re-certified by a hydrostatic testing facility before they are deemed safe for further use. Unfortunately, the cost of testing/re-certification generally exceeds the cost of a new tank, so most players just opt to buy a new one. It is wise to regularly inspect your air tanks before each time you play. Check for leaks, dents, damages or other questionable signs of wear. Also check the tank’s valve or regulator to be sure it isn’t loose in the tank. Never remove or try to install the CO2 tank valves; this should only be done by a professional that has been trained in maintaining high pressure compressed gas equipment. As a general rule, if your tank springs a leak, get away from it until it empties; then take it to a professional for repair or simply buy a new one. If you are ever in doubt, don’t hesitate to contact the manufacturer or distributor of the product for advice.